By: Mrs. Crisp The Inner Planets

S.P.I – Distinguish among the planets according to their known characteristics such as appearance, location, composition, and apparent motion – Select information from complex data representation to draw conclusions about the planets.

Academic Vocabulary Solar System A star and the objects that orbit around it. Planet A large planet that orbits a star and does not produce its own light. Moon A natural object that orbits a planet.

Academic Vocabulary Asteroid A rock that revolves around the sun. Revolution One complete trip of one object around another object. Rotation A complete spin on an axis. One

What are planets? Solar System A star and the objects that orbit around it. In our solar system, there are 8 planets orbiting the sun. Planet A large object that orbits a star. Moon A natural object that orbits a planet. All but two planets in our solar system have one or more moons.

What are planets? From nearest to farthest from the Sun, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. The planets travel in an elliptical, circular motion around the sun.

What are planets? The inner planets are closest to the sun. These planets are also “terrestrial planets” because their surfaces are made up of rock. These planets are Mercury, Venus, Earth and Mars. Inner Planets MercuryVenus EarthMars

What are planets? The outer planets are furthest from the sun. These planets are also “gaseous planets” because they are slushy balls of liquid and gas. These planets are Jupiter, Saturn, Uranus and Neptune and they all four have rings. Outer Planets JupiterSaturn UranusNeptune

What are planets? Revolution One complete trip around the sun. Rotation A complete spin on an axis.

What do we know about Mercury? (35 x 15 x 13 miles) in size Mercury is the closest planet to the sun. Mercury is the smallest planet in the universe. Mercury is 1/3 the size of earth. Scientist think Mercury has a large nickel-iron core. Scientist think some of its core is molten. It take Mercury 88 days to make one revolution around the sun. Mercury rotates on it’s axis once every 59 days. Mercury has no true atmosphere but hydrogen, helium, argon, and oxygen have been detected. Temperatures at night are extremely low on Mercury.

What do we know about Venus? (35 x 15 x 13 miles) in size Venus is the second planet from the sun (67 million miles away). Venus is almost the same size as Earth. Venus is covered with volcanoes, lava flows, huge mountains, craters, and large plains. One day on Venus is longer than its year. Venus revolves around the sun in 225 days. Venus rotates in the direction opposite of Earth. Venus has a dense atmosphere of carbon dioxide and is covered by a thick layer of clouds. Temperatures are very high on Venus (usually 900 ৹ F). Venus has yellow clouds of sulfuric acid (precipitation is like acid rain on Earth, only worse). Venus is the brightest planet in Earth’s sky because it is the closest. Scientist think Venus’s interior is similar to Earth’s. Venus has pressures 90x greater than Earth’s enough to crash a space craft.

What do we know about Earth? (35 x 15 x 13 miles) in size Earth is the third planet from the sun. Earth is the largest inner planet. There may once have been craters on Earth but erosion have caused these to disappear. Earth is the only planet know to support life. Earth’s atmosphere keeps it from getting too hot or too cold. It’s atmosphere is made up of nitrogen (78%) and oxygen (21%) Producers release oxygen into the atmosphere through photosynthesis. An earth day is 24 hours long. An earth year is 365 days long.

What do we know about Mars? (35 x 15 x 13 miles) in size Mars is the fourth planet from the sun. Mars rotates every 24.6 hours. Mars year is twice as long as Earth’s. Mars’ axis is tilted 25 ৹, which means it also has seasons. Scientists have discovered volcanoes on Mars (one three times as high as Mount Everest!) Mars has a very thin atmosphere (95% carbon dioxide, 2.7% nitrogen, 1.6% argon. The sky appears to be pink from the reddish dust in the atmosphere. The interior make-up of Mars is unknown. Ice caps made of frozen carbon dioxide and water can be found at both of the poles of Mars. Mars is known as the “Red Planet”.